Cooking Directions

Beat together butter, sugar, yolk, milk, and vanilla with an electric mixer until blended well. Sift in flour, cocoa, and salt and beat on low speed until mixture forms a dough. Chill, wrapped in plastic wrap, until firm, at least 30 minutes.

Preheat oven to 350 F.

Roll scant tablespoons of dough into balls, then coat with egg white, letting excess drip off, and roll in nuts to coat. Arrange balls, as coated, 1 1/2 inches apart on greased baking sheets and press your thumb into center of balls to flatten, leaving a depression. Bake in batches in middle of oven until puffed slightly but centers are soft, 10 to 12 minutes. Remove from oven and immediately press centers of cookies again (we used handle end of a wooden spoon). Transfer to racks to cool.

Make filling while cookies cool, and one hour before serving make the chocolate drizzle.

Caramel Filling

Heat caramels and cream in a small saucepan over moderately low heat, stirring occasionally, until melted and mixture is smooth. Spoon into centers of cookies and cool completely.

Chocolate Drizzle

Melt chocolate in a double boiler or a metal bowl set over a pan of barely simmering water, stirring until smooth.

Cool to warm and pour into a heavy-duty sealable plastic bag. Seal bag and snip 1 corner to form a small hole. Drizzle chocolate over the cookies and let stand until set, about 30 minutes.